import sharp from "sharp"

export interface ImageOptions {
    width?: number
    height?: number
    quality?: number
    format?: string // "webp", "jpeg", "png", "avif"
}

export async function optimizeImage(buffer: Buffer, options: ImageOptions): Promise<{ buffer: Buffer; contentType: string; filename: string }> {
    let pipeline = sharp(buffer)

    // Resize if width or height is provided and greater than 0
    if ((options.width && options.width > 0) || (options.height && options.height > 0)) {
        pipeline = pipeline.resize({
            width: options.width && options.width > 0 ? options.width : undefined,
            height: options.height && options.height > 0 ? options.height : undefined,
            fit: "cover", // Or 'contain', 'fill' based on requirement. Cover is usually good for heroes.
            withoutEnlargement: true,
        })
    }

    // Default format is AVIF if not specified
    const format = options.format?.toLowerCase() || "avif"
    const quality = options.quality && options.quality > 0 ? options.quality : 80

    switch (format) {
        case "jpeg":
        case "jpg":
            pipeline = pipeline.jpeg({ quality })
            break
        case "png":
            pipeline = pipeline.png({ quality, compressionLevel: 9 }) // PNG quality is different, usually compression level
            break
        case "webp":
            pipeline = pipeline.webp({ quality })
            break
        case "avif":
            pipeline = pipeline.avif({ quality })
            break
        default:
            pipeline = pipeline.avif({ quality })
            break
    }

    const processedBuffer = await pipeline.toBuffer()
    const extension = format === "jpg" ? "jpeg" : format

    return {
        buffer: processedBuffer,
        contentType: `image/${extension}`,
        filename: `image.${extension}`, // Generic filename, caller can prepend/append if needed
    }
}